Spreader stoker apparatus



Jan. 13, 1948.

s. H. CHAPMAN SPREADER STOKER APPARATUS Filed Aug. 21, 1943 lz L-J INVENTOR Stuart A! Chapman ATTORNEY Patented Jan. 13, 1948 SPREADER STOKER APPARATUS Stuart H. Chapman, Lima, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application August 21, 1943, Serial No. 499,525

2 Claims.

This invention relates to stokers of the spreader or sprinkler type, more particularly to fuel impellers therefor, and has for an object to provide improved fuel-impelling members.

In certain types of spreader stoker installations, it is desirable that the fuel be deposited on the grate in a front-to-rear lane of uniform limited width. The spreaders heretofore used have deposited the fuel on the grate in a lane of nonuniform width, the lane being narrow near the front of the stoker, and materially wider at the central and rear portions.

This uneveness in the width of the fuel lane is due, in part, to the fact that the larger pieces of fuel are projected farther than the smaller ones, the smaller pieces falling on the forward portion of the grate and the larger pieces falling on the central and rearward portions. When irregularly shaped larger pieces are struck by the conventional rotating impeller blade, they are frequently deflected sidewise beyond the desired lateral limitations of the fuel path.

The present invention has for an object the provision of a fuel-impelling blade, so constructed as to eliminate the objectionable sidewise deflection of irregularly shaped pieces of fuel. This is accomplished by providing a blade whose fuel-engaging face is formed with a plurality of concavities, preferably in the form of half cylinders, the end or side portions of the convavities serving to guide and direct the fuel to the central or bottom portion of the concavity where all the fuel coming within the range of the concavity is massed, with the result that the various pieces of fuel are no longer projected onto the fuel bed individually but as groups, thereby preventing the objectionable deflection of individual irregular pieces.

These and other objects are effected by the invention as will be apparent from the followin description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is .a, longitudinal sectional view through spreader stoker apparatus embodying the present invention;

Fig. 2 is a plan view of a portion of the apparatus shown in Fig. 1, with portions thereof broken away for the sake of clearness; and,

Fig. 3 is an enlarged fragmentary view of the rotor and blade construction of Figs. 1 and 2.

Referring now to the drawings more in detail, and particularly to Figs. 1 and 2, the reference character l indicates, in its entirety, spreader mechanism for delivering fuel through the open- 2 ing II in the front wall l2 of the furnace l3, to the grate structure l4 within the latter.

The spreader mechanism comprises a hopper it from which fuel discharges by gravity to the bottom plate ll of the ram box I8. As best indicated in Fig. 2, the ram box is provided with a plurality of vertical partitions [9 extending from front to rear thereof and serving to space the series of rams 20, 2'1, 22 and 23.

Reciprocatory motion is imparted to the rams through a linkage arrangement comprising links 23 or 21 connected at one end to a ram and at the other end to one end of a bar 28, fixedly secured on the vertical shaft 30, which shaft is journaled for limited rotary motion in the lower and upper support plates 3| and 32, respectively, carried by the ram box structure l8. Extending rearwardly from each vertical shaft is a lever arm 34, disposed at right angles to the arm 2'8 and having their free ends pivotally connected to the transversely-extending shaft or bar by pins 35. Transverse reciprocatory motion is imparted to the bar by suitable means, such as the engine 31, operating through the link 38, having .a slot-and-pin connection 39 with the bar 35.

In order to prevent clogging of the ram structure by fuel siftings working forwardly into the ram box, the latter is provided with an interior groove or recess 40 having inlet and outlet connections Ma and Nb, respectively, whereby air or liquid may be continuously passed through the groove 40 to remove siftings finding their way thereto through the joints between the rams and the ram box structure.

Fuel, pushed rearwardly from the bottom plate of the ram box structure by reciprocation of the rams, moves over the supporting plate 42, upon which a plurality of spill plates 43, 44, and 46 are adapted to reciprocate.

As best illustrated in Fig. 2, the number of spill plates preferably coincides with the number of rams, and the correspondin spill plates and rams are arranged to reciprocate in phase, that is, when ram 23 moves rearwardly its corresponding spill plate 43 likewise moves rearwardly. Also, it will be noted that alternate spill plates and rams (2U, 43 and 22, 45) reciprocate in one direction when the remaining spill plates and rams (2|, 44 and 23, 46) reciprocate in the opposite direction, this arrangement providing for more uniform feed of fuel than would be possible if all of the rams were advanced and retracted in unison. However, it will be apparent that corresponding spill plates and rams may be reciprocated out of phase and that all spill plates and/or all rams may reciprocate in unison or in any desired manner.

The means herein illustrated for reciprocating each spill plate comprises a rod 48 connected at its rearward end to the forward portion of the spill plate and having at its forward end a depending lug 49, which is bifurcated to receivethe rearward'end- 50 of a connecting link theend 50 being secured within the bifurcation of the depending lug 49 by the pin 52', for pivotal move.- ment. The forward end of the link 5| is secured by pin 53 between the arms of the bifurcated lever 54, which is fixedly secured to the lower portion of the vertical shaft, 30;. Preferably; each member 54 is of double arm construction, and.

has attached to the other arm linkage. similar to. that just described, for operating the'adjacent spill plate. Preferably, there is included in each link 5|, suitable stroke-adjusting mechanism, in-

dicated. at 55. Inasmuch as the stroke-adjust-- ing mechanism comprises no part of the present invention, it. is indicated only schematically in the accompanying drawings,

Inorder that the spill plates may reciprocate freely beneath the fuel being fed rearwardly thereover, the plates are tapered at their forward edges, as at 58, with the result that they may easily slide beneath; the fuel deposited upon the supporting plate 42. It will be apparent that reciprocation of the spill plates provides for feeding, offuel to the impeller. or rotor mechanism: 59,, from points varying from rearwardly of the vertical. centerlineof the rotor to forward-- ly' thereof, with the result thatv the fuel. is. pro-- jected through angles varying from the. horizontal; thereby providing improved distribution of fuellengthwise of the grade structure [4.

The impeller 59- is enclosed by a housing Bil, disposed in close proximity to the path of the tips of the impeller blades. The impeller 59 comprises a hollow'cylinder' or drum 6l= mounted upon ahorizontally-disposed shaft 62, which may be connected, by the coupling 63, to the driving: shaft 64 of a suitable engine (not shown). The hollow cylinder or drum 6| is provided with a plurality of blade members 66, each blade member comprising a plurality of semi-cylindrical members 61 having concave fuel-engaging surfaces 68, the members 61 being joined to' form the single fuel-impelling member 66', by suitable weld deposits: 69 and 10.

While, in the arrangement herein illustrated, the: semi-cylindrical members 61 are associated to provide two longitudinally extending unitary blade members 66, it will be apparent that any number of such. longitudinally extendingblade members may be provided and that, if desired, the length of these blade members may be less than that illustrated and the arrangement there- 4 of about the periphery of the hollow drum 6| may be varied as desired. Obviously, single semicylindrical members 61 may be spaced about the drum as desired, thereby providing more uniform delivery of fuel to the grates.

In operation, the fuel falling into the path of any one semi-cylindrical member 61 will be guided and directed, by the side or end walls of the concave surface 68, to the central or bottom portion thereof, and the mass of fuel so collected will then be thrown rearwardly, as a mass, onto the grates [4.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What is claimed is:

1. In a .stoker, fuel-feeding means comprising a rotatable body member and a plurality of U-shaped fuel-impelling members carried by the body member with the legs of the U-members extending forwardly in the direction of rotation and the concaved bottoms of said U-members being curved about axes extending substantially radially of the axis of rotation of the body member, whereby the concave portions of the U-members engage the fuel and direct the substantial portionthereof normal to a plane including the axis of rotation of the body member.

2. In a stoker, fuel-feeding means comprising a rotatable body member and a plurality of fuelimpelling members carried thereby, said fuelimpellin members having fuel-contacting faces deeply concaved about axes extending substantially radially of the axis of rotation of the body member and adapted to project the substantial portion of the fuel in a direction normal to a plane including the axis of rotation of the body member.

STUART H. CHAPMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,191,270 Campbell et al. Feb. 20, 1940 1,048,756 Stover Dec. 31, 1912 2,004,363 Beers June 11, 1935 1,975,224 Cox Oct. 2, 1934 984,715 Swift Feb. 21, 1911 FOREIGN PATENTS Number Country Date 26,096 Austria Oct. 25, 1906 

